DESCRIPTION: Molecules 2D simulates the interaction of charged particles in a two dimensional plane. The particles interact via the classical Coulomb force, as well as the repulsive quantum-mechanical Pauli force, which acts at close distances (accounting for the "collisions" between them). Additionally, the motion of the particles is damped by a term proportional to their velocity, allowing them to "settle down" into stable (or meta-stable) states.

Moving in response to these forces, the particles will eventually end up in a configuration of minimum potential, where the net force on any given particle is essentially zero. Generally, individual particles will first pair off into dipoles and then slowly combine into larger structures. Rings and straight lines are the most common configurations, but by clicking and dragging particles around, they can be coaxed into more complex meta-stable formations. Pressing "m" while the simulation is paused will generate a two-dimensional map of the potential field generated by the particles, where red represents a strong positive potential and black represents a strong negative potential. This process may take a few seconds when a large number of particles are involved.